Staple buttress retention system

ABSTRACT

A surgical stapling instrument is provided having systems for securing buttress material to the anvil and staple containing cartridge associated with the surgical instrument. The system includes a retainer configured to engage the anvil or the staple containing cartridge and capture the buttress material between the retainer and the anvil or staple containing cartridge. The disclose retainer engages the anvil or staple containing cartridge in snap fit or friction fit fashion. The buttress material includes a circumferential perforation line enabling the center of the buttress material to be stapled to tissue while the remainder of the buttress material remains with the anvil or staple containing cartridge.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/235,825 filed on Sep. 19, 2011, now U.S. Pat. No. 8,256,654, which isa divisional of U.S. application Ser. No. 11/807,144 filed on May 25,2007, now U.S. Pat. No. 8,038,045, and the disclosures of each of theabove identified applications is hereby incorporated by reference intheir entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to the application of buttress materialsused in joining body tissue and attachment systems for attachingbuttress materials to surgical instruments. More particularly, thepresent disclosure relates to systems and methods of temporarilyattaching staple line buttress materials to the anvil and/or staplecontaining cartridge of a surgical stapling instrument.

2. Background of Related Art

Surgical stapling devices are employed by surgeons to sequentially orsimultaneously apply one or more rows of fasteners, e.g., staples ortwo-part fasteners, to body tissue for the purpose of joining segmentsof body tissue together. Such devices generally consist of a pair ofjaws or finger-like structures between which the body tissue to bejoined is placed. When the stapling device is actuated, or “fired”, afiring member or members contact staple drive members in one of thejaws. The staple drive members push the surgical staples through thebody tissue and into an anvil in an opposite jaw which crimps thestaples closed. If tissue is to be removed or separated, a knife bladecan be provided in the jaws of the device to cut the tissue between thelines of staples.

When stapling relatively thin diseased, or fragile tissues, a buttressmay be used to seal the staple line against air or fluid leakage.Additionally, a buttress may be used to reinforce the staple lineagainst the tissue to prevent tears in the tissue or pulling of thestaples through the tissue. A layer of buttress material is placedagainst the tissue and the tissue is stapled in conventional manner. Itis known to position the buttress material on the stapling instrumentitself prior to stapling the tissue. An exemplary example of this isdisclosed in U.S. Pat. No. 5,542,594 to McKean et al. In McKean et al.the buttress material is slipped over the jaw of the stapler. Thestapler is then actuated to staple the subject tissue and secure thebuttress material between the tissue and staple line to reinforce thetissue and staple line.

It would be desirable to provide a system of attaching a limited amountof buttress material to a surgical instrument such that the material islocalized on the jaws of the surgical instrument. It would also bedesirable to provide a system of attaching buttress material to asurgical instrument that facilitates the release of the buttressmaterial from the surgical instrument. Additionally, while the methoddisclosed in McKean is useful for open surgical procedures, it would bedesirable to provide a system of attaching buttress material to the jawsof an endoscopic instrument. It would further be desirable to provide asystem of attaching buttress material to the anvil and staple containinghead of a circular surgical stapling instrument.

SUMMARY

There is disclosed a surgical instrument having a system of retainingbuttress material. The surgical instrument includes a handle and anelongate member extending distally from the handle. A jaw assembly ismounted on the distal end of the elongate member and includes an anviland a staple containing cartridge. A buttress retainer, having an opencenter, is positioned at least partially within the staple containingcartridge such that the buttress retainer frictionally engages thestaple containing cartridge. The buttress material is positioned betweenthe staple containing cartridge and the buttress retainer. The staplecontaining cartridge includes an outer channel having raised edges and astaple containing insert positioned within the outer channel. Thebuttress retainer frictionally engages the raised edges of the staplecontaining cartridge.

In one embodiment, the insert includes a side notch and the retainerincludes a depending leg such that the depending leg sits in the sidenotch and frictionally engages the outer channel. In one embodiment theretainer is a circular ring for use with a circular surgical staplinginstrument while in an alternative embodiment the retainer is rectanglefor use with a linear surgical stapling instrument. In the alternativeembodiment, at least one end of the retainer includes a notch configuredto be cut by a blade of the surgical instrument.

In a particular embodiment, the buttress material includes acircumferential perforation line separating a central portion of thebuttress material from a peripheral portion of the buttress materialsuch that the central portion can be staple the tissue while the outerportion remains with the staple containing cartridge.

There is also disclosed the system of securing a buttress material tothe anvil of a surgical instrument. A buttress retainer is configured toslide over the anvil such that the buttress retainer releasably retainsat least a portion of the buttress material against the anvil. Thebuttress retainer includes a first rail and a second rail configured tobe slid over the edges of the anvil. The first rail includes a first leghaving a first inwardly directed lip configured to engage in edge of theanvil. In one embodiment, the first leg is flexible. The buttressretainer additionally includes an open center portion. In a specificembodiment, the buttress material includes a circumferential perforationline.

There is also disclosed an alternative system for securing a buttressmaterial to the anvil of a surgical instrument. A buttress retainer isconfigured to engage the anvil in snap fit fashion such that thebuttress retainer releasably retains the buttress material against theanvil. The buttress retainer includes at least one flexible leg havingan inwardly directed projection configured to engage an edge of theanvil.

In one embodiment, the anvil is configured for use with a circularsurgical stapling instrument. In this particular embodiment, the atleast one flexible leg and inwardly directed projection are configuredto engage a rim of an anvil cap of the anvil.

In an alternative embodiment, the anvil is configured for use with alinear surgical stapling instrument.

In a specific embodiment, buttress material includes a circumferentialperforation line allowing a center portion of the buttress material tobe stapled to tissue while the remainder of the buttress materialremains with the anvil and buttress retainer.

DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed systems for attachingstaple line buttress materials to a surgical stapling instrument aredisclosed herein with reference to the drawings, wherein:

FIG. 1 is a perspective view of a surgical stapling instrumentincorporating a system for attachment of staple line buttress materials;

FIG. 2 is a perspective view of the distal end of the surgical staplinginstrument of FIG. 1;

FIG. 3 is a perspective view, with parts separated, of an anvil andbuttress material attachment system;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a perspective view of the distal end of the surgical staplinginstrument of FIG. 1;

FIG. 6 is a perspective view, with parts separated, of one embodiment ofa staple cartridge and buttress material attachment system;

FIG. 7 is a perspective view of a sheet of buttress material configuredfor use with the system illustrated in FIG. 6;

FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 5illustrating one embodiment of an attachment system;

FIG. 9 is a cross-sectional view similar to FIG. 8 illustrating analternative embodiment of an attachment system;

FIG. 10 is a perspective view of the distal end of the surgical staplinginstrument in position on tubular tissue;

FIG. 11 is a cross-sectional view of a tissue section captured betweenan anvil and staple cartridge of the surgical instrument of FIG. 1;

FIG. 12 is a cross-sectional view showing initial actuation of thesurgical stapling instrument of FIG. 1;

FIG. 13 is a perspective view of the distal end of the surgical staplinginstrument and stapled tissue sections;

FIG. 14 is a cross-sectional view of the stapled tissue section takenalong line 14-14 of FIG. 13;

FIG. 15 is a perspective view of a circular stapling instrument inaccordance with one embodiment of a buttress material attachment system;

FIG. 16 is a perspective view, with parts separated, of the distal endof the circular surgical stapling instrument of FIG. 15;

FIG. 17 is a side view, partially shown in section, of the distal end ofthe circular surgical stapling instrument of FIG. 15 positioned in atubular tissue section;

FIG. 18 is a side view illustrating the anvil of the circular surgicalstapling instrument attached to the stapling containing head of thecircular surgical stapling instrument;

FIG. 19 is a side view showing the anvil and staple containing headapproximated;

FIG. 20 is an enlarged area of detail view of FIG. 19;

FIG. 21 is a detail view showing actuation of the circular surgicalstapling instrument; and

FIG. 22 is a perspective view, partially shown in section, of thestapled tubular tissue sections.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed buttress material attachmentsystems for use with surgical instruments will now be described indetail with reference to the drawings wherein like numerals designateidentical or corresponding elements in each of the several views. As iscommon in the art, the term “proximal” refers to that part or componentcloser to the user or operator, i.e. surgeon or physician, while theterm “distal” refers to that part or component further away from theuser.

Referring now to FIG. 1, there is disclosed a linear surgical staplinginstrument or surgical stapler 10 for use in stapling tissue andapplying layers of buttress material between the staples and underlyingtissue. An example of this type of surgical stapling instrument isdisclosed in U.S. Pat. No. 7,044,353, the entire disclosure of which isincorporated by reference herein. Surgical stapler 10 generally includesa handle 12 having an elongate tubular member 14 extending distally fromhandle 12. A jaw assembly 16 is mounted on a distal end 18 of elongatetubular member 14. Jaw assembly 16 includes a staple forming anvil 20and a staple containing cartridge or staple cartridge 22. Staplecartridge 22 may be permanently affixed to elongate tubular member 14 ormay be detachable and thus replaceable with a new staple cartridge 22.Staple clinching anvil 20 is movably mounted on distal end 18 ofelongate tubular member 14 and is movable between an open positionspaced apart from staple cartridge 22 to a closed position substantiallyadjacent staple cartridge 22.

Staple forming anvil 20 is provided with a layer of anvil buttressmaterial 24 and staple cartridge 22 is provided with a layer ofcartridge buttress material 26 in the manners described in more detailhereinbelow. The type of buttress material on the anvil 20 may be thesame or different from the type of buttress material on the staplecartridge. An anvil buttress retainer 28 is provide to releasably secureanvil buttress material to staple forming anvil 20. Likewise, acartridge buttress retainer 30 is provided to releasable securecartridge buttress material 26 to staple cartridge 22. Anvil buttressmaterial 24 and cartridge buttress material 26 are provided toreinforce, seal, and/or otherwise support staple lines applied to tissueby surgical stapler 10.

Surgical stapler 10 includes a trigger 32 movably mounted on handle 12.Actuation of trigger 32 initially operates to move anvil 20 from theopen to the closed position relative to staple cartridge 22 andsubsequently actuate surgical stapler 10 to apply lines of staples totissue. In order to properly orient jaw assembly 16 relative to thetissue to be stapled, surgical stapler 10 is additionally provided witha rotation knob 34 mounted on handle 12. Rotation of rotation knob 34relative to handle 12 rotates elongate tubular member 14 and jawassembly 16 relative to handle 12 so as to properly orient jaw assembly16 relative to the tissue to be stapled.

Referring to FIG. 2, a driver 36 is provided to move anvil 20 betweenthe open and closed positions relative to staple cartridge 22. Driver 36moves through a longitudinal slot 38 formed in anvil 20. A knife blade(not shown) is associated with driver 32 to cut tissue captured betweenanvil 20 and staple cartridge 22 as driver 36 passes through slot 38.

Anvil 20, anvil buttress material 24 and anvil buttress retainer 28combine to form an anvil buttress attachment system 40 allowing anvilbuttress material 24 to be supported on and releasably affixed to anvil20. Similarly, staple cartridge 22, cartridge buttress material 26 andcartridge buttress retainer 30 combine to form a cartridge buttressattachment system 42 allowing cartridge buttress material 26 to besupported on and releasably affixed to staple cartridge 22. Anvilbuttress attachment system 40 and cartridge buttress attachment system42 are particularly configured to allow the respective buttressmaterials to be localized on inwardly facing surfaces of anvil 20 andstaple cartridge 22 in order to facilitate passage of surgical stapler10 into the body of a patient without risk of tearing or wrinkling ofthe respective buttress materials as surgical stapler 10 is insertedinto and manipulated within the body of a patient.

Referring to FIG. 3, in order to move anvil 20 between the open andclosed positions, anvil 20 includes a proximal, angled or sloped edge 44configured to be engaged by driver 36 in order to cam anvil 20 to theclosed position. Slot 38 extends distally from sloped edge 44 andterminates in a transverse slot 46 which is configured to capture driver36 upon complete actuation of surgical stapler 10 to prevent any furtheractuation of surgical stapler 10. In order to secure staples provided bystaple cartridge 22 about the tissues and buttress materials, anvil 20is provided with longitudinally extending rows of staple clinchingpockets 48 located on either side of longitudinal slot 38. While only asingle row of staple clinching pockets 48 is illustrated on either sideof slot 38, it is contemplated that multiple and/or staggered rows ofstaple clinching pockets 48 may be provided on anvil 20.

Referring still to FIG. 3, anvil buttress attachment system 40,including anvil 20, anvil buttress material 24 and anvil buttressretainer 28 will now be described. The buttress material for the staplecartridge 22 and/or anvil 20 may be made from any biocompatible naturalor synthetic material. The material from which the buttress material isformed may be bioabsorbable or non-bioabsorbable. It should of course beunderstood that any combination of natural, synthetic, bioabsorbable andnon-bioabsorbable materials may be used to form the buttress material.

Some non-limiting examples of materials from which the buttress materialmay be made include but are not limited to poly(lactic acid), poly(glycolic acid), poly (hydroxybutyrate), poly (phosphazine), polyesters,polyethylene glycols, polyethylene oxides, polyacrylamides,polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinylalcohols, polyacrylic acid, polyacetate, polycaprolactone,polypropylene, aliphatic polyesters, glycerols, poly(amino acids),copoly (ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyalkylene oxalates, polyoxaesters,polyorthoesters, polyphosphazenes and copolymers, block copolymers,homopolymers, blends and combinations thereof.

In embodiments, natural biological polymers are used in forming thebuttress material. Suitable natural biological polymers include, but arenot limited to, collagen, gelatin, fibrin, fibrinogen, elastin, keratin,albumin, hydroxyethyl cellulose, cellulose, hydroxypropyl cellulose,carboxyethyl cellulose, chitan, chitosan, and combinations thereof. Inaddition, the natural biological polymers may be combined with any ofthe other polymeric materials described herein to produce the buttressmaterial.

The buttress material may be porous or non-porous, or combinations ofporous and non-porous layers. Where the buttress material is non-porous,buttress material may retard or prevent tissue ingrowth from surroundingtissues thereby acting as an adhesion barrier and preventing theformation of unwanted scar tissue. Thus, in embodiments, the buttressmaterial possesses anti-adhesion properties. Techniques for formingnon-porous layers from such materials are within the purview of thoseskilled in the art and include, for example, casting, molding and thelike.

In embodiments, the buttress material is porous and possesses hemostaticproperties. Where the buttress material is porous, it has openings orpores over at least a portion of a surface thereof. Suitable materialsfor forming the porous layer include, but are not limited to foams(e.g., open or closed cell foams). In embodiments, the pores may be insufficient number and size so as to interconnect across the entirethickness of the porous layer. In other embodiments, the pores do notinterconnect across the entire thickness of the porous layer. In yetother embodiments, the pores do not extend across the entire thicknessof the porous layer, but rather are present at a portion of the surfacethereof. In embodiments, the openings or pores are located on a portionof the surface of the porous layer, with other portions of the porouslayer having a non-porous texture. Those skilled in the art reading thepresent disclosure will envision other pore distribution patterns andconfigurations for the porous layer.

Where the buttress material is porous, the pores may be formed using anymethod suitable to forming a foam or sponge including, but not limitedto the lyophilization or freeze-drying of a composition. Suitabletechniques for making foams are within the purview of those skilled inthe art. Porous buttress materials can be at least 0.2 cm thick, inembodiments from about 0.3 to about 1.5 cm thick. Porous buttressmaterials can have a density of not more than about 75 mg/cm² and, inembodiments below about 20 mg/cm². The size of the pores in the porousbuttress materials can be from about 20 μm to about 300 μm, inembodiments from about 100 μm to about 200 μm.

The buttress material may also include a reinforcement member. Thereinforcement member may be associated with a porous or non-porous layeror may be positioned between a non-porous layer and a porous layer ofthe buttress material. Alternatively, the reinforcement member may bepositioned entirely within one or more of the individual layers (i.e.,embedded within the porous layer, the non-porous layer, or both) of thebuttress material. It is also envisioned that the reinforcement membermay be positioned at the surface of one of the layers making up thebuttress material and, in embodiments, may be positioned at an exteriorsurface of the buttress material.

Some suitable non-limiting examples of reinforcement members includefabrics, meshes, monofilaments, multifilament braids, chopped fibers(sometimes referred to in the art as staple fibers) and combinationsthereof. Where the reinforcement member is a mesh, it may be preparedusing any technique known to those skilled in the art, such as knitting,weaving, tatting, knipling or the like. Where monofilaments ormultifilament braids are used as the reinforcement member, themonofilaments or multifilament braids may be oriented in any desiredmanner. For example, the monofilaments or multifilament braids may berandomly positioned with respect to each other within the buttressmaterial. As another example, the monofilaments or multifilament braidsmay be oriented in a common direction within the buttress material.Where chopped fibers are used as the reinforcement member, the choppedfibers may be oriented in any desired manner. For example, the choppedfibers may be randomly oriented or may be oriented in a commondirection. The chopped fibers can thus form a non-woven material, suchas a mat or a felt. The chopped fibers may be joined together (e.g., byheat fusing) or they may be unattached to each other. The chopped fibersmay be of any suitable length. For example, the chopped may be from 0.1mm to 100 mm in length, in embodiments, 0.4 mm to 50 mm in length. In anillustrative embodiment, the buttress material has randomly orientedchopped fibers that have not been previously fused together embeddedwithin in the buttress material.

It is envisioned that the reinforcement member may be formed from anybioabsorbable, non-bioabsorbable, natural, or synthetic materialpreviously described herein and combinations thereof. Wheremonofilaments or multifilament braids are used as the reinforcementmember, any commercially available suture material may advantageously beemployed as the reinforcement member.

In embodiments, at least one bioactive agent may be combined with thebuttress material and/or any of the individual components (the porouslayer, the non-porous layer and/or the reinforcement member) used toconstruct the buttress material. In these embodiments, the buttressmaterial can also serve as a vehicle for delivery of the bioactiveagent. The term “bioactive agent”, as used herein, is used in itsbroadest sense and includes any substance or mixture of substances thathave clinical use. Consequently, bioactive agents may or may not havepharmacological activity per se, e.g., a dye, or fragrance.Alternatively a bioactive agent could be any agent which provides atherapeutic or prophylactic effect, a compound that affects orparticipates in tissue growth, cell growth, cell differentiation, ananti-adhesive compound, a compound that may be able to invoke abiological action such as an immune response, or could play any otherrole in one or more biological processes.

Examples of classes of bioactive agents which may be utilized inaccordance with the present disclosure include anti-adhesives,antimicrobials, analgesics, antipyretics, anesthetics, antiepileptics,antihistamines, anti-inflammatories, cardiovascular drugs, diagnosticagents, sympathomimetics, cholinomimetics, antimuscarinics,antispasmodics, hormones, growth factors, muscle relaxants, adrenergicneuron blockers, antineoplastics, immunogenic agents,immunosuppressants, gastrointestinal drugs, diuretics, steroids, lipids,lipopolysaccharides, polysaccharides, and enzymes. It is also intendedthat combinations of bioactive agents may be used.

Anti-adhesive or anti-adhesion agents can be used to prevent adhesionsfrom forming between the buttress material and the surrounding tissuesopposite the target tissue. Some examples of these agents include, butare not limited to poly(vinyl pyrrolidone), carboxymethyl cellulose,hyaluronic acid, polyethylene oxide, poly vinyl alcohols andcombinations thereof.

Suitable antimicrobial agents which may be included as a bioactive agentin the buttress material of the present disclosure include triclosan,also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether, chlorhexidineand its salts, including chlorhexidine acetate, chlorhexidine gluconate,chlorhexidine hydrochloride, and chlorhexidine sulfate, silver and itssalts, including silver acetate, silver benzoate, silver carbonate,silver citrate, silver iodate, silver iodide, silver lactate, silverlaurate, silver nitrate, silver oxide, silver palmitate, silver protein,and silver sulfadiazine, polymyxin, tetracycline, aminoglycosides, suchas tobramycin and gentamicin, rifampicin, bacitracin, neomycin,chloramphenicol, miconazole, quinolones such as oxolinic acid,norfloxacin, nalidixic acid, pefloxacin, enoxacin and ciprofloxacin,penicillins such as oxacillin and pipracil, nonoxynol 9, fusidic acid,cephalosporins, and combinations thereof. In addition, antimicrobialproteins and peptides such as bovine lactoferrin and lactoferricin B maybe included as a bioactive agent in the bioactive coating of the presentdisclosure.

Other bioactive agents which may be included as a bioactive agent in thebuttress material in accordance with the present disclosure include:local anesthetics; non-steroidal antifertility agents;parasympathomimetic agents; psychotherapeutic agents; tranquilizers;decongestants; sedative hypnotics; steroids; sulfonamides;sympathomimetic agents; vaccines; vitamins; antimalarials; anti-migraineagents; anti-parkinson agents such as L-dopa; anti-spasmodics;anticholinergic agents (e.g. oxybutynin); antitussives; bronchodilators;cardiovascular agents such as coronary vasodilators and nitroglycerin;alkaloids; analgesics; narcotics such as codeine, dihydrocodeinone,meperidine, morphine and the like; non-narcotics such as salicylates,aspirin, acetaminophen, d-propoxyphene and the like; opioid receptorantagonists, such as naltrexone and naloxone; anti-cancer agents;anti-convulsants; anti-emetics; antihistamines; anti-inflammatory agentssuch as hormonal agents, hydrocortisone, prednisolone, prednisone,non-hormonal agents, allopurinol, indomethacin, phenylbutazone and thelike; prostaglandins and cytotoxic drugs; estrogens; antibacterials;antibiotics; anti-fungals; anti-virals; anticoagulants; anticonvulsants;antidepressants; antihistamines; and immunological agents.

Other examples of suitable bioactive agents which may be included in thecoating composition include viruses and cells, peptides, polypeptidesand proteins, analogs, muteins, and active fragments thereof, such asimmunoglobulins, antibodies, cytokines (e.g. lymphokines, monokines,chemokines), blood clotting factors, hemopoietic factors, interleukins(IL-2, IL-3, IL-4, IL-6), interferons (β-IFN, (α-IFN and γ-IFN),erythropoietin, nucleases, tumor necrosis factor, colony stimulatingfactors (e.g., GCSF, GM-CSF, MCSF), insulin, anti-tumor agents and tumorsuppressors, blood proteins, gonadotropins (e.g., FSH, LH, CG, etc.),hormones and hormone analogs (e.g., growth hormone), vaccines (e.g.,tumoral, bacterial and viral antigens); somatostatin; antigens; bloodcoagulation factors; growth factors (e.g., nerve growth factor,insulin-like growth factor); protein inhibitors, protein antagonists,and protein agonists; nucleic acids, such as antisense molecules, DNAand RNA; oligonucleotides; polynucleotides; and ribozymes.

Referring still to FIG. 3, anvil buttress attachment system 40,including anvil 20, anvil buttress material 24 and anvil buttressretainer 28 will now be described. Referring to FIGS. 3 and 4, as shown,buttress retainer 28 is configured to releasably retain buttressmaterial 24 against the face of anvil 20. Buttress retainer 28 isconfigured to slip or snap over anvil 20 to retain buttress material 24.Buttress retainer 28 includes a frame 50 defining a open center area 52through which staples associated with staple cartridge 22 pass. Frame 50includes a distal end 54 and a proximal end 56. First and second sides58 and 60, respectively, extend between distal end 54 and proximal end56. A first leg 62 depends from first side 58 and includes a firstinwardly directed lip 64. Similarly, a second leg 66 depends from secondside 60 and includes a second inwardly directed lip 68. First side 58,first leg 62 and first lip 64 form a first rail 70 for receipt of anvil20 and second side 60, second leg 66 and second lip 68 form a secondrail 72 for receipt of anvil 20.

Anvil buttress retainer 28 is affixed to anvil 20 by longitudinallysliding anvil buttress retainer 28 over anvil 20 such that first rail 70slides over and frictionally engages a first side 74 of anvil 20 andsecond rail 72 slides over and frictionally engages a second side 76 ofanvil 20 thereby trapping anvil buttress material between anvil buttressretainer 28 and anvil 20. Anvil buttress material 24 is exposed throughopen center 52 to staple cartridge 22. Anvil buttress material 24 isloosely retained between anvil buttress retainer 28 and anvil 20 suchthat, upon stapling anvil buttress material 24 to tissue, anvil buttressmaterial 24 can pull free of anvil 20. First lip 64 and second lip 68are sized to releasably retain the buttress material 24 and to allow thebuttress material 24 to pull free of anvil 20 in use. Alternatively,anvil buttress material 24 can be firmly grasped between anvil 20 andanvil buttress retainer 28. In this embodiment, anvil buttress material24 is formed with a circumferential perforation line 78 allowing acenter portion 80 of anvil buttress material to pull apart from aperipheral portion 82 upon stapling center portion 80 to tissue.Peripheral portion 82 is captured and retained between anvil 20 andanvil buttress retainer 28.

In a further alternative embodiment, first and second legs 62 and 66 maybe formed sufficiently flexible so as to snap fit over first and secondsides 74 and 76, respectively, of anvil 20 as opposed to beinglongitudinally slid over anvil 20. Anvil buttress material 24 is thencaptured between anvil 20 and anvil buttress retainer 28 in any of themethods discussed hereinabove.

Referring to FIG. 5, and as noted hereinabove, jaw assembly 16 hascartridge buttress attachment system 42 including staple cartridge 22and cartridge buttress material 30 secured to staple cartridge 22 bycartridge buttress retainer 30. Staple cartridge 22 is a known type ofstaple cartridge having a generally U-shaped outer channel 84 and astaple containing insert 86 positioned within outer channel 84. In aparticular embodiment outer channel 84 is formed of stamped sheet metalwhile staple containing insert 86 is formed from a plastic material.

Referring now to FIG. 6, outer channel 84 includes a U-shaped proximalend 88 which allows staple cartridge 22 to be removably attached toelongate tubular member 14. Staple containing insert 86 includes acentrally located elongated slot 90 for passage of a knife associatedwith surgical stapler 10. Additionally, staple containing insert 86includes longitudinally extending rows of staple containing pockets 92and 94 positioned on either side of slot 90. Pockets 92 and 94 containstaples and staple pushers in a manner described in more detailhereinbelow. Further, staple containing insert includes longitudinallyextending slots 96 and 98, positioned beneath rows of staple pockets 92and 94, for receipt of staple drive members 100 and 102. Passage ofstaple drive members 100 and 102 beneath staple containing pockets 92and 94 drive staples contained therein out of staple containing insert86.

In order to secure cartridge buttress retainer 30 to staple containingcartridge 22, outer channel 84 includes first and second longitudinallyextending raised edges 104 and 106 configured to capture cartridgebuttress retainer 30 therebetween. Cartridge buttress retainer 30includes a distal end 108 and a proximal end 110. First and second sides112 and 114 extend between distal end 108 and proximal end 110. Whencartridge buttress retainer 30 is assembled to staple containingcartridge 22, first side 112 frictionally engages first raised edge 104while second side 114 frictionally engages second raised edge 106 thusfirmly securing cartridge buttress retainer 30 between first and secondraised edges 104 and 106 of outer channel 84 of staple containingcartridge 22.

Referring for the moment to FIG. 7, similar to staple buttress material24 described hereinabove, cartridge buttress material 26 is providedwith a circumferential perforation line 116 separating a peripheralportion 118 from a central portion 120 of cartridge buttress material26.

Referring back to FIG. 6, in order for a knife blade (not shown),associated with surgical stapling instrument 10, to completely cutcartridge buttress material 26, distal end 108 of cartridge buttressretainer 30 is provided with a notch 122 and the cartridge buttressretainer 30 is configured at the notch 122 to be cut by the knife blade.Similarly, proximal end 110 is provided with a notch 124 and thecartridge buttress retainer 30 is configured at notch 124 to be cut by aknife blade during cutting of cartridge buttress material 26. The anvilbuttress retainer 28 is similarly configured to be cut by the knifeblade while remaining attached to anvil 20.

Referring now to FIG. 8, as discussed hereinabove, cartridge buttressmaterial 26 is secured between cartridge buttress retainer 30 and staplecontaining insert 86 of staple cartridge 22. Specifically, peripheralportion 118 of cartridge buttress material 26 is trapped between firstside 112 of cartridge buttress retainer 30 and staple containing insert86. Central portion 120 of cartridge buttress material 26 is free to bestapled to tissue and separated from peripheral portion 118 alongperforation line 116. As shown, first side 112 of cartridge buttressretainer 30 is frictionally retained by first raised edge 104 of outerchannel 84. Alternatively, the perforation line 116 is omitted and thedistal end 108, proximal end 110, first side 112 and/or second side 114are sized to releasably retain buttress material 26 while allowing thebuttress material 26 to slip through the open center area of thecartridge buttress retainer 30.

Referring for the moment to FIG. 9, an alternative method of securingcartridge buttress retainer 30 within staple cartridge 22 isillustrated. In this embodiment, staple containing insert 86 includes aside notch 126 which is configured to receive a depending leg 128extending downwardly from first side 112 of cartridge buttress retainer30. Specifically, depending leg 128 is captured between staplecontaining insert 86 and outer channel 84. Similar to the embodimentdisclosed in FIG. 8, peripheral portion 118 of cartridge buttressmaterial 26 is captured between first side 112 and staple containinginsert 86. Central portion 120 is free to separate along perforationline 116 after being stapled to tissue.

Referring now to FIGS. 10 through 14, and initially with respect toFIGS. 10 and 11, the use of surgical stapler 10 to staple and divide atubular tissue section T will now be described. Initially, jaw assembly16, including anvil 20 and staple containing cartridge 22 are positionedaround the tissue T to be stapled. Driver 36 is in a proximal positionrelative to slot 38. As best shown in FIG. 11, staple containing insert86 includes staples 130 positioned within staple pockets 92. Staples 130are of a conventional type and include a backspan 132 having a pair oflegs 134 and 136 extending from backspan 132. Legs 134 and 136 terminatein tissue penetrating tips 138 and 140. Pushers 142 are located withinstaple pockets 92 and are positioned between staples 132 and the path ofdrive bar 100.

Referring now to FIG. 11, surgical stapler 10 is initially actuated bymovement of trigger 32 relative to handle 12 (FIG. 1) causing driver 36to move in the direction of arrow B and against sloped edge 44 of anvil20 thereby causing anvil 22 moved to the closed position relative tostaple cartridge 22. As best shown in FIG. 12, as drive bar 100 advancesdistally within staple containing insert 86, drive bar 100 urges pushers142 upwardly against backspans 132 of staples 130 driving staples in 30through cartridge buttress material 26, tissue T, anvil buttressmaterial 24 and towards staple forming pockets 48 in anvil 20. Tissuepenetrating tips 138 and 140 are bent within staple clinching pockets 48to thereby secure anvil buttress material 24 against tissue T whilebackspan 132 secures cartridge buttress material 26 against tissue T.

While not specifically shown, upon full actuation of surgical stapler10, a knife blade associated with surgical stapler 10 and carried bydriver 36 cuts tissue T, as well as anvil buttress material 24 andcartridge buttress material 26 between the rows of now formed staples132. As shown in FIG. 13, in one embodiment, upon movement of anvil 22to the open position, spaced apart from staple cartridge 22, anvilbuttress material 24 pulls away from anvil 20 as described hereinabove.In an alternative embodiment, peripheral portion 82 of anvil buttressmaterial 24 separates from central portion 80 along perforation line 78.Further, central portion 120 of cartridge buttress material 26 separatesfrom peripheral portion 118 along perforation line 116 (FIG. 7) in themanner described hereinabove. Thus, peripheral portions 82 and 118remain with anvil 20 and staple cartridge 22 as surgical stapler 10 ismoved away from tissue T.

The resulting tissue T stapled closed with staples 130 is bestillustrated in FIG. 14. Specifically, cartridge buttress material 26 issecured against tissue T by backspans 132 of staples 130 and anvilbuttress material 24 is secured against tissue T by the now formedtissue penetrating tips 138 and 140 of staples 130. In this manner,anvil buttress material 24 and cartridge buttress material 26 arestapled to tissue T thereby sealing and/or reinforcing these staplelines created by staples 130.

Referring now to FIGS. 15-22, and initially with respect to FIG. 15,systems for releasably attaching buttress materials to a circularsurgical stapler will now be described. Circular surgical stapler 150 isof known type generally including a handle 152 having an elongate member154 extending distally from handle 152. A staple containing head orcartridge 156 is provided on a distal end of elongate member 154. Staplecontaining cartridge 156 houses staples (not shown) for insertionthrough tissue. Specifically, circular surgical stapler 150 isconfigured to apply one or more circular rows of staples to stapletogether two tubular tissue sections. An anvil 160 is provided to formthe staples into a closed shape about tissue. Anvil 160 includes ananvil cap 162 having an anvil shaft 164 extending proximally from anvilcap 162. A shaft 166 extends from elongate member of 154 and isconfigured to releasably engage anvil shaft 164. An approximator 168 isrotatably mounted on handle 152 and is provided to approximate or moveanvil 160 toward and away from staple containing cartridge 156.

A pair of arms 170 are pivotally mounted on handle 152 and are providedto actuate circular surgical stapler 150 so as to eject staples (notshown) out of staple containing cartridge 156. A lock 172 is provided onhandle 152 to block and prevent actuation of circular surgical stapler150 prior to anvil 160 being approximated adjacent staple containingcartridge 156. Circular surgical stapler 150 is provided with an anvilbuttress material 174 releasably affixed to anvil cap 162 and acartridge buttress material 176 provided on staple containing cartridge156. Anvil buttress material 174 and cartridge buttress material 176serve to reinforce and/or seal a staple line applied to tubular tissuesections by circular surgical stapler 150.

Referring now to FIG. 16, staple containing cartridge 156 includes aplurality of staple pockets 178 containing staples as discussed in moredetail below. Similar to that discussed hereinabove with respect tostaple containing cartridge 22 of surgical stapler 10, in order toretain cartridge buttress material 176 on staple containing cartridge156, circular surgical stapler is provided with a system including acircular ring or cartridge buttress retainer 180. Cartridge buttressretainer 180 is configured to frictionally engage a raised distal outeredge 182 formed on staple containing cartridge 156 thereby capturingcartridge buttress material 176 between cartridge buttress retainer 180and staple containing cartridge 156. In one embodiment, cartridgebuttress material 176 fits loosely between cartridge buttress retainer180 and staple containing cartridge 156 such that, upon stapling totissue, cartridge buttress material 176 is free to pull away from staplecontaining cartridge 156. In an alternative embodiment, cartridgebuttress material 176 is provided with a circumferential perforationline 184 which allows a central portion of cartridge buttress material176 to pull away from the remainder of the buttress material capturedbetween staple containing cartridge 156 and cartridge buttress retainer180.

Anvil 160 includes a plurality of circumferentially spaced stapleforming pockets 186 formed in a face 188 of anvil cap 162 and configuredto form the staples after they have been driven through tissue. Circularsurgical stapler 150 is also provided with a system to retain anvilbuttress material 174 against anvil 160. A circular ring or anvilbuttress retainer 190 is provided having a circular frame 192 and aplurality of proximally facing legs or clips 194, 196 and 198 which areconfigured to engage a rim 200 of anvil cap 162. Specifically, clips194, 196 and 198 are provided with inwardly projecting lips 202, 204 and206 which are configured to engage rim 200 in a snap fit fashion.Similar to the system described hereinabove with respect to staplecontaining cartridge 156 and cartridge buttress material 176, in oneembodiment, anvil buttress material 174 is free to pull out from betweenanvil buttress retainer 190 and anvil 160. In an alternative embodiment,anvil buttress material 174 is provided with a circumferentialperforation line 208 which allows a center portion of anvil buttressmaterial 174 to be staple to tissue while leaving an outer portionsecured between anvil buttress retainer 190 and anvil 160.

As shown, in one embodiment, in order to secure anvil 160 to stapler150, there is provided an adapter 210. A proximal end 212 of adapter 210is configured to engage shaft 166 of circular surgical stapler 150.Adapter 210 includes a pointed distal end 214 configured to piercetissue sections as well as engage anvil shaft 164.

Referring now to FIGS. 15 and 17 to 22, and initially with regard toFIG. 17, the use of circular surgical stapler 150 to connect two tubulartissue sections and applied buttress material will now be described.Initially, staple containing cartridge 156 is positioned within a firsttubular tissue section T1 such that adapted 210 extends beyond tissueT1. A purse string suture 216 is formed about tissue T1 and adapter 210to form an inwardly directed tissue face TF1. Likewise, anvil 160 ispositioned within a second tubular tissue section T2 such that anvilshaft 164 projects beyond tissue section T2 and is secured thereto by asecond purse string suture 218 forming a second inwardly directed tissueface TF2. Adapter 210 is then inserted within anvil shaft 164 to connectstaple containing cartridge 156 to anvil 160. (FIG. 18)

Once staple containing cartridge 156 has been connected to anvil 160,approximator 168 on handle 152 is rotated to draw anvil 160 towardstaple containing cartridge 156 and thus bring first tissue face TF1into flush engagement with the second tissue face TF2 and in a positionto be stapled. (See FIGS. 1 and 19)

Referring to FIGS. 20 and 21, and as discussed hereinabove, staplecontaining cartridge 176 includes a plurality of staples 220. Circularsurgical stapler 150 is actuated by releasing lock 172 and pivoting arms170 (FIG. 1) thereby ejecting staples 220 out of staple containingcartridge 156 and through the tissue sections. Specifically, staples 220pass through first tissue face TF1, cartridge buttress material 176,second tissue face TF2 and anvil buttress material 174. Staples to 20are clinched closed about anvil buttress material 174 by stapleclinching pockets 186 (FIG. 16)

As best shown in FIG. 21, once tissues T1 and T2 have been stapledtogether, anvil 160 is separated from staple containing cartridge 156.In one embodiment, cartridge buttress material 176 pulls free fromcartridge buttress retainer 180 and anvil buttress material 174 pullsfree from anvil buttress retainer 190. In an alternative embodiment,cartridge buttress material 176 separates along circumferentialperforation line 184 and anvil buttress material 174 separates alongcircumferential perforation line 208.

The resultant stapled tissue sections are clearly illustrated in FIG.22. Once the tissue sections have been stapled, a circular knife (notshown) associated with circular surgical stapler 150 may be used to coreout portions of the stapled tissue sections.

It should be noted that the disclosed attachment systems allow thebuttress materials to be preloaded, i.e., positioned on the surgicalstapler at the time of manufacture eliminating the need for installationin the operating room. Additionally, since the buttress materials aregenerally localized on the faces of the anvil and staple cartridge, thesurgical stapler can be easily inserted through an access device withoutinterference from the buttress material. The attachment systems includecartridge buttress retainers and/or anvil buttress retainers that slideonto a surgical instrument, snap onto the instrument, adhere to theinstrument or frictionally engage the instrument, or any combinationthereof. The instrument can include a retainer for the cartridge, anvil,or both.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, the disclosed buttressmaterial retainer systems may be incorporated in open or endoscopicsurgical stapling instruments. Further, the disclosed buttress materialmay include central, or otherwise located, perforation lines tofacilitate separation of the buttress material from the associated anvilor staple containing cartridge. Additionally, the limited amount ofadhesive may be used to temporarily secure the buttress material to theanvil or staple containing cartridge. Therefore, the above descriptionshould not be construed as limiting, but merely as exemplifications ofparticular embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

The invention claimed is:
 1. An annular surgical stapling instrumenthaving a system for retaining buttress material comprising: a handle; anelongate member extending distally from the handle; an annular staplecontaining cartridge mounted adjacent a distal end of the elongatemember, the staple containing cartridge defining staple pockets forretaining staples; an annular anvil releasably connectable to theannular staple containing cartridge, the anvil defining staple formingpockets for forming staples ejected from the annular staple containingcartridge; at least one buttress material having a central portion and aperipheral portion separated by a perforation line wherein theperipheral portion surrounds the entire central portion of the at leastone buttress material; and at least one buttress retainer having a ringconfiguration defining an open center portion and being removablyattached to at least one of the staple containing cartridge and theanvil, each buttress retainer lying outwardly of the staple pockets forselectively retaining the peripheral portion of the buttress materialbetween the buttress retainer and a corresponding tissue contactingsurface of one of the staple containing cartridge and the anvil to whichthe buttress retainer is attached, the peripheral portion being retainedafter the buttress material has separated at the perforation line, andthe open center portion being sized to releasably retain the buttressmaterial, wherein the buttress retainer does not overlie the staplepockets provided in either of the staple containing cartridge or theanvil.
 2. The annular surgical stapling instrument according to claim 1,wherein the buttress retainer is engaged with the staple containingcartridge.
 3. The annular surgical stapling instrument according toclaim 1, wherein a buttress material is frictionally captured betweenthe buttress retainer and at least one of the staple containingcartridge or the anvil.
 4. An annular surgical stapling instrument,comprising: an annular staple containing cartridge defining a tissuecontacting surface; an annular anvil defining a tissue contactingsurface, the anvil including staple forming pockets formed in the tissuecontacting surface thereof for forming staples expelled fromcorresponding staple retaining slots defined in the tissue contactingsurface of the staple containing cartridge; a buttress material having acentral portion, a peripheral portion, and a perforation line separatingthe central portion from the peripheral portion, at least the peripheralportion being disposed against the tissue contacting surface of at leastone of the staple containing cartridge and the anvil, the centralportion of the buttress material being separable from the peripheralportion of the buttress material after staples are fired by the surgicalinstrument; and a buttress material retainer for securing at least aportion of the buttress material against the tissue contacting surfaceof at least one of the staple containing cartridge and the anvil, thebuttress material retainer including a frame configured to overlie thebuttress material and extend around at least a portion of the perimeterof the peripheral portion of the buttress material, wherein, upon afiring of the surgical stapling instrument, staples secure the centralportion of the buttress material against tissue and the frame retainsthe peripheral portion of the buttress material against the tissuecontacting surface of the at least one of staple containing cartridgeand the anvil, and wherein, upon separation of the at least one of thestaple containing cartridge and the anvil from the tissue, the centralportion of the buttress material is separated from the peripheralportion of the buttress material along the perforation line.
 5. Theannular surgical stapling instrument according to claim 4, wherein thebuttress material retainer includes at least one depending leg forengaging a side edge of at least one of the staple containing cartridgeand the anvil.
 6. The annular surgical stapling instrument according toclaim 5, wherein the at least one depending leg of the buttress materialretainer includes an inwardly directed projection configured to engagethe side edge of one of the staple containing cartridge and the anvil,to retain the edge of the corresponding staple containing cartridge andanvil between the inwardly directed projection and the buttress materialretainer.
 7. The annular surgical stapling instrument according to claim4, wherein the frame of the buttress material retainer is a circularring.
 8. The annular surgical stapling instrument according to claim 4,wherein each of the staple containing cartridge and the anvil includes abuttress material.
 9. The annular surgical stapling instrument accordingto claim 8, further comprising: a first buttress material retainer forretaining a first buttress material against the tissue contactingsurface of the staple containing cartridge; and a second buttressmaterial retainer for retaining a second buttress material against thetissue contacting surface of the anvil, wherein each of the first andsecond buttress material retainers has an open center portion and isattached to its corresponding staple containing cartridge and anvil, andwherein the peripheral portion of each buttress material is retained byits respective buttress material retainer.
 10. The annular surgicalstapling instrument according to claim 9, wherein the buttress materialof the staple containing cartridge is different from the buttressmaterial of the anvil.
 11. A surgical stapling instrument having asystem of retaining buttress material comprising: an annular staplecontaining cartridge defining a tissue contacting surface; an annularanvil defining a tissue contacting surface, the anvil including stapleforming pockets formed in the tissue contacting surface thereof forforming staples expelled from corresponding staple retaining slotsdefined in the tissue contacting surface of the staple containingcartridge; and a buttress material having a central portion and aperipheral portion including a circumferential perforation lineseparating the central portion from the peripheral portion, theperipheral portion being attached to a tissue contacting surface of atleast one of the staple containing cartridge and the anvil, the centralportion being separable from the peripheral portion after staplescontained in the staple containing cartridge are fired, the buttressmaterial being preloaded on a surgical stapling instrument at the timeof manufacture.
 12. The surgical stapling instrument according to claim11, further comprising a buttress retainer having an open center portionand being attached to at least one of the staple containing cartridgeand the anvil, the peripheral portion of the buttress material beingretained against the tissue contacting surface of the at least one ofthe staple containing cartridge and the anvil by the buttress retainer.13. The surgical stapling instrument according to claim 12, wherein thebuttress retainer includes at least one depending leg for engaging atleast one of the staple containing cartridge and the anvil.
 14. Thesurgical stapling instrument according to claim 13, wherein the at leastone depending leg of the buttress retainer includes an inwardly directedprojection configured to engage an edge of one of the staple containingcartridge and the anvil, to retain the edge of the corresponding staplecontaining cartridge and anvil between the inwardly directed projectionand the buttress retainer.
 15. The surgical stapling instrumentaccording to claim 14, wherein the inwardly directed projection of theat least one depending leg of the buttress retainer is adapted to snapfit over the edge of the corresponding staple containing cartridge andanvil.
 16. The surgical stapling instrument according to claim 12,wherein the buttress retainer is a circular ring.
 17. The surgicalstapling instrument according to claim 16, wherein the circular ringincludes a plurality of depending legs for engaging at least one of thestaple containing cartridge and the anvil.
 18. The surgical staplinginstrument according to claim 17, wherein the plurality of dependinglegs each includes an inwardly directed projection configured to engagean edge of one of the first jaw and the second jaw, to retain the edgeof the corresponding staple containing cartridge and anvil between theinwardly directed projection and the buttress retainer.
 19. The surgicalstapling instrument according to claim 12, wherein the buttress retaineris configured to snap-fit over at least one of the first jaw and thesecond jaw such that the buttress retainer releasably retains thebuttress material along a periphery thereof.